Dynamic spray system

ABSTRACT

A dynamic spray system for effectively thermally managing electronic components. The dynamic spray system includes a thermal management system including a spray unit, and a control unit in communication with the thermal management system. The spray unit includes a spray head and an atomizer within the spray head for dispensing a continuous coolant spray having a spray characteristic. The control unit delivers an electrical signal to the spray unit dependent upon feedback data received from the thermal management system, wherein the electrical signal controls the spray unit to adjust the spray characteristic of the continuous coolant spray.

CROSS REFERENCE TO RELATED APPLICATIONS

I hereby claim benefit under Title 35, United States Code, Section 120of the following United States patent applications:

-   -   1. Ser. No. 11/107,350 filed Apr. 14, 2005 now abandoned;    -   2. Ser. No. 10/280,240 filed on Oct. 22, 2002 now U.S. Pat. No.        6,880,350; and    -   3. Ser. No. 10/243,683 filed Sep. 13, 2002 now U.S. Pat. No.        6,857,283.

This application is a continuation of the 11/107,350 application, filedApr. 14, 2005, now abandoned, which is a divisional of the Ser. No.10/280,240 application, filed Oct. 22, 2002, now U.S. Pat. No.6,880,350, which is a continuation-in-part of the Ser. No. 10/243,683application, filed Sep. 13, 2002, now U.S. Pat. No. 6,857,283. The Ser.No. 11/107,350 application Ser. No. 10/243,683 application and Ser. No.10/280,240 application are hereby incorporated by reference into thisapplication.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable to this application.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to thermal management systemsand more specifically it relates to a dynamic spray system for applyinga dynamic fluid spray to a surface and for thermally managing electroniccomponents.

2. Description of the Related Art

Thermal management systems for electronic devices have been in use foryears in applications such as but not limited to semiconductor burn-inand electronic component cooling. It is an objective of silicon devicemanufacturers to minimize burn-in time and simultaneously maintain thejunction temperatures of the batch of devices under burn-in to be withina narrow range. Conventional thermal management systems utilized todayare comprised of, for example, either air-cooled enclosures, orfluid-cooled cold plates. Upcoming technologies include refrigerationsystems or other phase change based technologies.

When producing semiconductors, manufacturers typically perform threedifferent tests on the semiconductors prior to shipping: (1) sort, (2)burn-in, and (3) class testing. Sort test requires maintaining thewafers at a modest temperature, e.g. 35° Celsius, while the wafers areprobed for defects. Conventional fluid-cooled cold plates are employedat this stage. Projected heat fluxes, even at the wafer sort, arepointing to the fact that a more effective thermal management technologyis needed at this stage.

Burn-in of the semiconductors is typically accomplished utilizingelevated voltages and temperatures in a process that raises the junctiontemperatures of a batch of semiconductors. The lifespan of asemiconductor is closely related to its operating temperature whereinoperating under increased temperatures reduces the effective lifespan ofthe semiconductor. By applying increased voltages and temperatures to asemiconductor, the weaker semiconductors will fail during testing. Thelength of the burn-in of semiconductors is directly tied to the medianjunction temperature of the batch of semiconductors. It is thereforeimportant to maintain a relatively narrow junction temperature spreadthat provides a higher median temperature. For example, a poor thermalmanagement system can produce a junction temperature spread from 75° to125° Celsius resulting in a low median junction temperature, longerburn-in time and higher associated burn-in costs. Modern fluid-basedthermal management systems are currently able to lower the junctiontemperature spread to approximately 95° to 110° Celsius thereby reducingburn-in time and burn-in costs.

Class test is the final step in the testing process and is comprised ofa final series of tests to validate functionality and quantify speeds.During class test, non-uniform heating of the semiconductors typicallyoccurs. A semiconductor's speed is typically derated by 0.15% for everydegree Celsius rise above the target temperature function temperature,Tj). It is therefore important to maintain the temperature of thesemiconductors relatively close to the target temperature (Tj).

Due to increasing chip heat fluxes (projected to exceed 125 W/cm² by theyear 2004), conventional thermal management systems for semiconductorburn-in are reaching their cooling limits. A further problem withconventional thermal management systems is that they are inefficient,complex, costly to implement and costly to operate. A further problemwith conventional thermal management systems is that the resultingjunction temperature spreads result in relatively long burn-in times ofthe semiconductor devices. Another problem with conventional thermalmanagement systems is that they require significant amounts of power tooperate.

Examples of patented devices which may be related to the presentinvention include U.S. Pat. No. 5,579,826 to Hamilton et al.; U.S. Pat.No. 5,582,235 to Hamilton et al.; U.S. Pat. No. 5,515,910 to Hamilton etal.; U.S. Pat. No. 5,359,285 to Hashinaga et al.; U.S. Pat. No.6,389,225 to Malinoski et al.; U.S. Pat. No. 6,114,868 to Nevill; U.S.Pat. No. 5,461,328 to Devereaux et al.; U.S. Pat. No. 6,181,143 toGhoshal; U.S. Pat. No. 6,288,371 to Hamilton et al.; U.S. Pat. No.5,532,610 to Tsujide et al.; U.S. Pat. No. 6,307,388 to Friedrich etal.; U.S. Pat. No. 6,175,498 to Conroy et al.; U.S. Pat. No. 6,359,456to Hembree et al.; U.S. Pat. No. 5,541,524 to Tuckerman et al.; U.S.Pat. No. 5,220,804 to Tilton et al.; U.S. Pat. No. 6,016,969 to Tiltonet al.; U.S. Pat. No. 6,108,201 to Tilton et al.; U.S. Pat. No.6,104,610 to Tilton et al.; U.S. Pat. No. 5,880,931 to Tilton et al.;U.S. Pat. No. 5,933,700 to Tilton; U.S. Pat. No. 5,713,327 to Tilton etal.; U.S. Pat. No. 5,860,602 to Tilton et al.; U.S. Pat. No. 5,314,529to Tilton et al.; U.S. Pat. No. 6,205,799 to Patel et al.; U.S. Pat. No.6,349,554 to Patel et al.; U.S. Pat. No. 5,380,956 to Loo et al.; U.S.Pat. No. 6,115,251 to Patel et al.; U.S. Pat. No. 6,421,240 to Patel;and U.S. Pat. No. 6,317,326 to Vogel et al. Examples of patentapplications filed for devices that may be related to the presentinvention include U.S. Patent Application 2001/0002541 filed by Patel etal.; U.S. Patent Application 2002/0050144 filed by Patel et al.; andU.S. Patent Application 2001/0050164 filed by Wagner et al.

Hence, the dynamic spray system according to the present inventionsubstantially departs from the conventional concepts and designs of theprior art, and in so doing provides an apparatus primarily developed forthe purpose of effectively thermally managing electronic components.

BRIEF SUMMARY OF THE INVENTION

In view of the foregoing disadvantages inherent in the known types ofsemiconductor burn-in systems now present in the prior art, the presentinvention provides a new dynamic spray system construction wherein thesame can be utilized for effectively thermally managing electroniccomponents.

The general purpose of the present invention, which will be describedsubsequently in greater detail, is to provide a new dynamic spray systemthat has many of the advantages of the thermal management and liquiddispersing systems mentioned heretofore and many novel features thatresult in a new dynamic spray system which is not anticipated, renderedobvious, suggested, or even implied by any of the prior artsemiconductor burn-in systems, either alone or in any combinationthereof.

To attain this, the present invention generally comprises one or morespray units each having a housing structure, a first portion, a firstorifice within said first portion fluidly connected to a swirl chamber,a main jet fluidly connected to the swirl chamber, a plunger movablypositioned within the main jet for adjusting fluid flow through the mainjet, and at least one swirl inlet fluidly connected to the swirl chamberfor generating a fluid swirl effect within the swirl chamber. The mainjet is preferably aligned with the first orifice for dispersing arelatively narrow spray pattern from the first orifice when the fluidflow is increased through the main jet. The spray pattern size isincreased when the fluid flow through the main jet is decreased.

There has thus been outlined, rather broadly, the more importantfeatures of the invention in order that the detailed description thereofmay be better understood and in order that the present contribution tothe art may be better appreciated. There are additional features of theinvention that will be described hereinafter and that will form thesubject matter of the claims appended hereto.

In this respect, before explaining at least one embodiment of theinvention in detail, it is to be understood that the invention is notlimited in its application to the details of construction and to thearrangements of the components set forth in the following description orillustrated in the drawings. The invention is capable of otherembodiments and of being practiced and carried out in various ways.Also, it is to be understood that the phraseology and terminologyemployed herein are for the purpose of the description and should not beregarded as limiting.

A primary object of the present invention is to provide a dynamic spraysystem that will overcome the shortcomings of the prior art devices.

A second object is to provide a dynamic spray system that achieves aminimum junction temperature spread between chips burned-insimultaneously in a batch.

A further object is to provide a dynamic spray system that thermallymanages electronic components.

A further object is to provide a dynamic spray system that may beutilized within various applications including but not limited toburn-in thermal management, thermally managing electronic components,and applying a fluid to a surface in a dynamic manner.

Another object is to provide a dynamic spray system that provides anefficient system for adjusting the spray pattern emitted from a sprayunit.

An additional object is to provide a dynamic spray system that is energyefficient, flexible and relatively small in size.

A further object is to provide a dynamic spray system that is lesscostly to implement and operate than conventional thermal managementsystems.

Another object is to provide a dynamic spray system that reduces testingtimes of semiconductor devices.

An additional object is to provide a dynamic spray system that transfersheat from a semiconductor using conduction, convection, phase change ora combination thereof.

Another object is to provide a dynamic spray system that works withexisting and various types of burn-in equipment currently utilized inthe industry.

Another object is to provide a dynamic spray system that is capable ofmanaging the temperature of semiconductors that utilize an integratedheat sink and semiconductors that do not utilize an integrated heatsink.

Other objects and advantages of the present invention will becomeobvious to the reader and it is intended that these objects andadvantages are within the scope of the present invention.

To the accomplishment of the above and related objects, this inventionmay be embodied in the form illustrated in the accompanying drawings,attention being called to the fact, however, that the drawings areillustrative only, and that changes may be made in the specificconstruction illustrated and described within the scope of the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

Various other objects, features and attendant advantages of the presentinvention will become fully appreciated as the same becomes betterunderstood when considered in conjunction with the accompanyingdrawings, in which like reference characters designate the same orsimilar parts throughout the several views, and wherein:

FIG. 1 is a schematic diagram illustrating the overall structure of thepresent invention.

FIG. 2 is a block diagram illustrating the communication connectionsbetween the control unit and the related components of the presentinvention.

FIG. 3 is a flowchart illustrating the overall operation of the presentinvention.

FIG. 4 is an upper perspective view of a spray unit.

FIG. 5 is a top view of the spray unit.

FIG. 6 is a side cutaway view of an individual swirl chamber with theplunger fully inserted within the main jet.

FIG. 7 is a side cutaway view of an individual swirl chamber with theplunger partially removed from the main jet.

FIG. 8 is a side cutaway view of the spray unit with the plungers fullyinserted within the corresponding main jets.

FIG. 9 is a side cutaway view of the spray unit with the plungerspartially removed from the corresponding main jets.

FIG. 10 is a cross sectional view taken along line 10-10 of FIG. 6.

FIG. 11 is a cross sectional view taken along line 11-11 of FIG. 7.

FIG. 12 is a cross sectional view of an embodiment of the presentinvention having more than one swirl inlet.

DETAILED DESCRIPTION OF THE INVENTION A. Overview

Turning now descriptively to the drawings, in which similar referencecharacters denote similar elements throughout the several views, FIGS. 1through 12 illustrate a dynamic spray system 10, which comprises one ormore spray units 40 each having a housing structure 42, a first portion50, a first orifice 52 within said first portion 50 fluidly connected toa swirl chamber 30, a main jet 35 fluidly connected to the swirl chamber30, a plunger 37 movably positioned within the main jet 35 for adjustingfluid flow through the main jet 35, and at least one swirl inlet 32fluidly connected to the swirl chamber 30 for generating a fluid swirleffect within the swirl chamber 30. The main jet 35 is preferablyaligned with the first orifice 52 for dispersing a relatively narrowspray pattern from the first orifice 52 when the fluid flow is increasedthrough the main jet 35. The spray pattern is broadened when the fluidflow through the main jet 35 is decreased.

B. Spray Enclosures

Spray enclosures 20 are known within the semiconductor burn-in industry.A typical spray enclosure 20 has an interior cavity for receiving atleast one burn-in board. The spray enclosure 20 may be comprised of anystructure capable of housing a burn-in board which are commonly utilizedwithin the burn-in industry or other unit not utilized within theburn-in industry. The spray enclosure 20 preferably has an opening and adoor for selectively closing and sealing the opening as is conventionalwith spray enclosures 20 utilized within the burn-in industry. The sprayenclosure 20 preferably has a rail structure or other structure forreceiving and supporting one or more burn-in boards 12 in a desiredposition with respect to the corresponding spray assembly having one ormore spray units 40. It can be appreciated that the spray assemblies andthe burn-in boards 12 may be stacked within the interior cavity of thespray enclosure 20 depending upon the total number of burn-in boards 12to be utilized simultaneously. An inlet tube extends into the sprayenclosure 20 for providing the fluid to the spray assembly as will bediscussed in further detail. An outlet tube extends from the sprayenclosure 20 returning the fluid recovered from the spray enclosure 20to the reservoir 80.

It can be appreciated that the spray enclosure 20 may have variousstructures and configurations that may be suitable for usage with thepresent invention. U.S. Pat. No. 5,880,592 provides an exemplary burn-inspray enclosure 20.

C. Burn-In Board

Burn-in boards 12 are also commonly utilized within the burn-inindustry. The burn-in board 12 typically includes one or more sockets 14arranged in a desired pattern. Each of the sockets 14 removablyreceives, through an opening, a semiconductor 18 to be tested during theburn-in phase. The fluid is sprayed from the spray unit 40 through thisopening to engage a surface of the semiconductor 18 contained within thesocket 14 for maintaining the desired temperature of the semiconductors18 within.

The sockets 14 are electrically connectable to the semiconductor 18inserted within the respective sockets 14. The burn-in board 12 is thenelectrically coupled to a control unit 60 via a communications port orother structure attached to the burn-in board 12 that controls the testsignals sent to each of the semiconductors 18 during the burn-in testingprocedure. U.S. Pat. Nos. 6,404,219, 6,181,146 and 5,825,171 illustrateexemplary burn-in devices and burn-in systems which are suitable forusage with the present invention. It can be appreciated that variousother burn-in board 12 structures and configurations may be utilizedwith the present invention.

D. Temperature Sensor

In order to measure the temperature of the semiconductors 18 duringtesting, a temperature sensor 62 may be attached to each of the sockets14, directly upon the semiconductors 18, embedded directly within thesemiconductors 18, or positioned within the spray units 40. Devices formeasuring the temperature of semiconductors 18 are commonly utilizedwithin the burn-in industry that may be utilized with the presentinvention. Examples of suitable temperature sensors 62 include but arenot limited to thermocouple, thermopile, electronic devices capable ofinferring temperature of the semiconductor 18 from the semiconductor'spower draw, or infrared devices. FIGS. 8 and 9 illustrate the usage ofan infrared device for the temperature sensor 62 which detects thetemperature of the semiconductor 18 through an aperture within the firstportion 50 of the spray unit 40.

E. Spray Units

A plurality of spray units 40 may be organized within an array forming aspray assembly. The spray assembly preferably is comprised of arelatively flat structure, however various other structures may beutilized to construct the spray assembly. Each of the spray units 40 ispreferably arranged upon the spray assembly corresponding to a specificsocket 14 within the burn-in board 12. There may or may not be a patternfor the plurality of spray units 40 such as but not limited to a rowpattern, or a staggered pattern.

Each of the spray units 40 includes a housing structure 42 having aninterior housing cavity 43 covered by a rear plate or other similarstructure. The rear plate may be attached to the housing structure 42using various fastening devices. The housing structure 42 may havevarious sizes and shapes other than illustrated in the drawings. A firstport 45 is fluidly connected within the housing structure 42 whichfluidly corresponds to the main jet 35 and the swirl inlets 32 of thespray units 40.

Each of the spray units 40 has a first portion 50 containing one or morefirst orifices 52. The spray units 40 may be comprised of variousmovable components which are not shown in the attached drawings, butwhich may be easily adapted to utilize the present invention. The firstportion 50 may have various shapes and structures for dispensing thefluid onto the semiconductor 18.

One or more first orifices 52 extend through the first portion 50 invarious patterns as best shown in FIGS. 4 and 5 of the drawings. Thefirst orifices 52 may have various characteristics, shapes, sizes,styles, designs, arrangements and densities. The first orifices 52 maybe arranged to provide various spray patterns amongst multiple orifices,or various cone angles from each individual first orifice 52, upon thesemiconductor 18. Cone angles may be of the full cone variety as isknown in the art, or of the hollow cone variety as is also known in theart, and may vary from 10° to 60°, but are not limited to varieties, orthis angular range. The first orifices 52 provide an adjustable spraypattern depending upon the temperature and/or heat flux of thesemiconductor 18 being tested. The first orifices 52 dispense thepressurized fluid from within the swirl chamber 30 as shown in FIGS. 6through 9 of the drawings.

Dynamic spray cone angles are utilized dependent upon the thermalmanagement requirements of the semiconductor 18. For example, if it isdesirable to reduce the cooling of the semiconductor 18, one or more ofthe orifices 52 may be adjusted to reduce the surface area that issprayed with the fluid by adjusting the spray cone angles in response totemperature feedback. Conversely, if it is desirable to increase thecooling of the semiconductor 18, one or more of the orifices 52 may beadjusted to increase the surface area that is sprayed with the fluid byadjusting the spray cone angles in response to temperature feedback. Theorifices 52 could be aligned to correspond to high heat flux areas onthe semiconductor 18.

The spray assembly may include a first inlet port that is fluidlyconnected to the housing cavity 43 and the swirl inlets 32 of the sprayunits 40. A first valve 84 preferably controls the fluid flow from aninlet tube to the first inlet port. The first port 45 within the sprayunits 40 receives the fluid flow from the first inlet port therebyproviding the pressurized fluid to the housing cavity 43 of the sprayunits 40. The main jet 35 and the swirl inlets 32 preferably receive thepressurized fluid from the housing cavity 43 as best illustrated inFIGS. 8 and 9 of the drawings.

In an alternative embodiment, the swirl inlets 32 may receive thepressurized fluid from a different source than the main jet 35. In thealternative embodiment, a second valve may separately control the fluidflow from the inlet tube to a second inlet port within the spray unit40. A second port within the spray unit 40 receives the fluid flow fromthe second inlet port for providing the pressurized fluid to the swirlinlets 32.

F. Dynamic Spray Control

FIGS. 6 through 9 of the drawings illustrate an exemplary dynamic spraycontrol within the spray units 40. The dynamic spray control may be usedfor one or more of the first orifices 52. As shown in FIGS. 6 through 9,a swirl chamber 30 is positioned within the first portion 50 of thespray unit 40. The swirl chamber 30 is fluidly connected to the firstorifice 52 as best illustrated in FIGS. 6 and 7 of the drawings.

The swirl chamber 30 preferably has a cylindrical interior with acircular cross section for facilitating the rotation of fluid within theswirl chamber 30. However, the swirl chamber 30 may have various othercross sectional shapes such as but not limited to square or oval. Theswirl chamber 30 may have various sizes, interior heights and interiordiameters.

As shown in FIGS. 6 through 12 of the drawings, one or more swirl inlets32 are fluidly connected to the swirl chamber 30 for providing a fluidflow into the swirl chamber 30 relatively transverse with respect to thedirection of spray from the first orifice 52. The swirl inlets 32 arepreferably substantially tangential to the interior wall of the swirlchamber 30 as best illustrated in FIGS. 10 through 12 of the drawings.The swirl inlets 32 fluidly extend within the spray unit 40 and arepreferably are fluidly connected to the housing cavity 43, oralternatively to a second port.

An inlet plate 33 partially surrounds the swirl chamber 30 opposite ofthe first orifice 52 as best illustrated in FIGS. 6 and 7 of thedrawings. The inlet plate 33 may have various thicknesses, however it ispreferable to maintain the thickness of the inlet plate 33 between0.005-0.20 inches. A thicker inlet plate 33 provides increased controlover the fluid flow as the length of the tapered portion 38 of theplunger 37 may be increased.

As best shown in FIGS. 6 and 7 of the drawings, a main jet 35 extendswithin the inlet plate 33 and fluidly connects the housing cavity 43 andthe swirl chamber 30. The main jet 35 preferably has a constant innerdiameter as best illustrated in FIGS. 6 and 7 of the drawings. However,tapered or varying structures may be utilized to construct the main jet35. The main jet 35 preferably has a circular cross section, howevervarious other cross sectional shapes may be utilized to construct themain jet 35 such as but not limited to square, rectangular and oval.

The main jet 35 is preferably aligned coaxially with the first orifice52 as illustrated in FIGS. 6 and 7 of the drawings. However, the mainjet 35 may be positioned offset with respect to an axis of the firstorifice 52. Alternatively, more than one main jet 35 may extend throughthe inlet plate 33 into the swirl chamber 30.

As shown in FIGS. 6 and 7 of the drawings, a plunger 37 having a taperedportion 38 is movably positioned within the main jet 35. The plunger 37controls the amount of fluid that flows through the main jet 35 basedupon the position of the plunger 37 within the main jet 35. The taperedportion 38 preferably has a constant taper as illustrated in FIGS. 6 and7, however the tapered portion 38 may have a varying tapered structurefor providing various flow control. A stepped structure may also beutilized upon the distal portion of the plunger 37. In addition, aplunger 37 may be positioned within the swirl inlet 32 for controllingthe fluid flow through the swirl inlet 32.

Various technologies may be utilized to control the position of theplunger 37 within the main jet 35 such as but not limited to digitalstepper motors, linear actuators, magnetostrictive actuators ormechanical devices. In addition, each plunger 37 may be controlledindividually or in a group by using a common mechanical or electricalstructure by the control unit 60.

FIGS. 8 and 9 illustrate the usage of a main plate 70 secured within thehousing cavity 43 of the spray unit 40 which allows for the passage offluid through thereof through openings. A support plate 76 is connectedto the main plate 70 by a biasing device such as but not limited to oneor more springs 74 as further shown in FIGS. 8 and 9 of the drawings. Aplanar magnet 72 is attached to the support plate 76 with a magneticcoil 90 positioned within the spray unit 40 for generating a magneticfield that either repels or attracts the planar magnet 72 with respectthereto thereby causing the support plate 76 to move accordingly. Themagnetic coil 90 is electrically connected to the control unit 60 whichprovides the electrical power required to generate the desired magneticfield. Various other actuator devices, which are commonly utilized inthe electronics industry, may be utilized to manipulate the supportplate 76.

One or more plungers 37 are connected to the support plate 76 in anon-movable manner as shown in FIGS. 6 through 9 of the drawings. Theplungers 37 are manipulated within their respective main jet 35 as shownin FIGS. 8 and 9 of the drawings. It is preferable to have all of theplungers 37 within one or more spray units 40 to be connected to asingle support plate 76 for providing a uniform manipulation of theplungers 37. However, the plungers 37 may be attached singularly and/orin groups to a support plate 76 within a spray unit 40 so as to providediverse control of the spray pattern emitted from the first orifices 52.

Alternatively, moving the inlet plate 33 and the first portion 50 withrespect to the plunger 37 positioned in a stationary position may beutilized instead of moving the plunger 37. Various other devices may beutilized to control the flow of fluid into the swirl chamber 30 andthereby control the characteristics of the fluid spray dispersed fromthe first orifice 52. A piezo-crystal or magnetostrictive materialpositioned between the inlet plate 33 and the walls of the swirl chamber30 may be utilized to manipulate the position of the inlet plate 33without the usage of a plunger 37 which disrupts the rotation of thefluid within the swirl chamber 30.

As the fluid flows into the swirl chamber 30 from the main jet 35, thefluid is combined with fluid flowing into the swirl chamber 30transversely from one or more swirl inlets 32 creating a swirlingrotation effect within the swirl chamber 30. Increased rotation of thefluid within the swirl chamber 30 provides for increased atomization ofthe fluid upon being dispersed through the first orifice 52 and a largerspray pattern.

Relatively low fluid flow through the main jet 35 with respect to theswirl inlet 32 allows for increased rotation of the fluid within theswirl chamber 30 that increases the size and angle of the spray patternas illustrated in FIGS. 6, 8 and 10 of the drawings. Relatively highfluid flow through the main jet 35 with respect to the swirl inlet 32allows for decreased rotation of the fluid within the swirl chamber 30thereby decreasing the size and angle of the spray pattern asillustrated in FIGS. 7, 9 and 11 of the drawings. By controlling therelative flow rate of fluid entering the swirl chamber 30 from the swirlinlet 32 and the main jet 35, the spray pattern is controllable asdesired.

As the plunger 37 is retracted from the main jet 35, an increased flowrate of the fluid is provided to the swirl chamber 30 thereby reducingthe amount of rotation of the fluid within the swirl chamber 30 as shownin FIGS. 7 and 9 of the drawings. The main jet 35 and the plunger 37 maybe sized such that when the plunger 37 is fully retracted from the mainjet 35, a relatively straight jet of fluid passes through the firstorifice 52 instead of an atomized spray. As the plunger 37 is extendedinto the main jet 35, a decreased flow rate of the fluid is provided tothe swirl chamber 30 thereby increasing the amount of rotation of thefluid within the swirl chamber 30 that occurs because of the swirl inlet32 as shown in FIGS. 6 and 8 of the drawings.

G. Fluid Distribution System

The reservoir 80 is comprised of a container structure capable ofretaining a desired volume of fluid. The reservoir 80 may have variousshapes, sizes and structures which are commonly utilized to construct areservoir 80. The fluid utilized within the present invention ispreferably comprised of a dielectric fluid such as but not limited tohydrofluoroether (HFE). However, the fluid utilized may be comprised ofa non-dielectric such as but not limited to water.

The reservoir 80 may include a thermal conditioning unit 66 forincreasing or decreasing the temperature of the fluid within thereservoir 80 to a desired temperature to be sprayed upon thesemiconductors 18 during the burn-in process. The thermal conditioningunit 66 may be comprised of a combination heater unit and cooling unit.A heat exchanger may be utilized to increase the temperature of thefluid within the reservoir 80 by exchanging the heat from the fluidreturning from the spray enclosure 20 after spraying upon thesemiconductors 18. An inline heater/cooler may also be utilized tothermally condition the fluid prior to or after spraying from thenozzles.

A main pump 82 is fluidly connected to the reservoir 80 for drawing thedielectric fluid from within the reservoir 80. The fluid pressure withinthe fluid distribution system may be maintained by operation of the mainpump 82 and/or a return valve 85 which allows for the return of fluid tothe reservoir 80 to lower the fluid pressure as shown in FIG. 1 of thedrawings. Various other pressure regulating devices may be utilized tocontrol the fluid pressure on the pressurized side of the pump. The mainpump 82 is fluidly connected to the first valve 84 as furtherillustrated in FIG. 1 of the drawings thereby providing pressurizedfluid to the spray units 40 at the desired pressure. Alternatively, if asecond fluid source is connected to the swirl inlets 32, a second valvemay be fluidly connected to the main pump 82.

As shown in FIG. 1 of the drawings, a fluid collector 28 is positionedwithin the spray enclosure 20 for collecting the fluid after beingsprayed upon the semiconductors 18. The fluid collector 28 may becomprised of various collecting devices such as but not limited to a panstructure. The fluid collector 28 is fluidly connected to the reservoir80 for returning the used fluid to the reservoir 80. A filter device maybe positioned within the fluid collector 28 or the reservoir 80 forfiltering the fluid after being sprayed upon the semiconductors 18 forremoving undesirable particulate materials and chemicals which mightinterfere with the operation of the spray units 40.

A vapor recovery unit 70 may be fluidly connected to or within the sprayenclosure 20 for collecting and condensing fluid that has undergone aphase change to vapor. The vapor recovery unit 70 may be comprised ofcondensing coils and similar other devices capable of condensing vapor.The vapor recovery unit 70 may be utilized during and after the burn-inprocess.

H. Control Unit

The control unit 60 may be comprised of various electronic devicescapable of communicating with and controlling the burn-in board 12, thethermal conditioning unit 66, the main pump 82, the first valve 84, thesecond valve, the return valve 85 and the vapor recovery unit 70. Thecontrol unit 60 may be comprised of a computer or other electronicdevice capable of receiving, storing and transmitting commands. Thecontrol unit 60 may be powered via various conventional electrical powersources.

The control unit 60 may communicate with the external electrical devicessuch as but not limited to electrically or via communications signal.The control unit 60 may be programmed to operate the external devices atvarious operating levels such as but not limited to controlling thetemperature of the fluid within the reservoir 80, controlling the fluidpressure and flow rate emitted by the main pump 82, controlling thespray pattern and flow of the first orifices 52, and controlling theflow of fluid to the spray unit 40. It can be appreciated that more thanone control unit 60 may be utilized to control one or more of thecomponents of the present invention.

I. Operation

In use, the semiconductors 18 are properly positioned within the sockets14 of the burn-board 12. The burn-in board 12 is then positioned withinthe spray enclosure 20 with the surface of the semiconductors 18 facingsubstantially toward the corresponding spray units 40. The dielectricfluid within the reservoir 80 is heated to a desired temperature forcooling or heating the semiconductors 18 with or without using aconditioning unit 90. The main pump 82 and first valve 84 may beutilized to achieve and maintain the target junction temperature eventhough the fluid temperature may not be the desired temperature. Themain pump 82 is operated to provide the pressurized fluid to the sprayassembly.

As the fluid is sprayed upon the semiconductor 18, the control unit 60applies the desired voltage to the semiconductors 18 through the burn-inboard 12 for burn-in testing purposes thereby increasing or lowering thetemperature of the semiconductor 18. If the temperature A of thesemiconductor 18 rises above a desired temperature B (e.g. 100°Celsius), then the flow rate X of the fluid may be increased to thespray units 40. In addition to or independent of increasing the flowrate X, the spray pattern size emitted from one or more of the firstorifices 52 may be increased to engage an increased surface area of thesemiconductor 18 of the semiconductor thereby increasing the cooling ofthe semiconductor 18 as shown in FIG. 3 of the drawings.

If the temperature A of the semiconductor 18 is lowered below a desiredtemperature B, then the flow rate X of the fluid may be decreased to thespray units 40. In addition to or independent of decreasing the flowrate X, the spray pattern size emitted from one or more of the firstorifices 52 may be decreased to engage a reduced surface area of thesemiconductor 18 thereby reducing the cooling of the semiconductor 18 asshown in FIG. 3 of the drawings. In addition, the spray pattern may beincreased in size thereby reducing the volume of spray engaging highheat flux areas of the semiconductor 18.

If the temperature A of the semiconductor 18 is approximately equal to adesired temperature B, then the flow rate X of the fluid is preferablymaintained to the spray units 40. In addition, the spray pattern size ispreferably maintained relatively constant for each of the first orifices52 where the temperature A of the semiconductor 18 is approximatelyequal to the desired temperature B.

In order to control the temperature A of the semiconductor 18, the powerlevel may also be increased or lowered independently or in conjunctionwith the control of the fluid flow rate. The AC and DC power levels maybe adjusted to manipulate the semiconductor's temperature.

This process continues until the semiconductors 18 are fully burned-inover the required amount of time. Once the burn-in process is completed,the flow of the fluid is terminated. All vapor is recovered during thefluid recovery phase, and unevaporated coolant on the burn-in board 12,sockets and other, is made to evaporate for subsequent recovery. Theburn-in board 12 and semiconductors 18 are then removed from the sprayenclosure 20 for replacement with other burn-in boards 12 andsemiconductors 18.

As to a further discussion of the manner of usage and operation of thepresent invention, the same should be apparent from the abovedescription. Accordingly, no further discussion relating to the mannerof usage and operation will be provided.

With respect to the above description then, it is to be realized thatthe optimum dimensional relationships for the parts of the invention, toinclude variations in size, materials, shape, form, function and mannerof operation, assembly and use, are deemed to be within the expertise ofthose skilled in the art, and all equivalent structural variations andrelationships to those illustrated in the drawings and described in thespecification are intended to be encompassed by the present invention.

In addition, the present invention should not be limited to solelysemiconductor burn-in applications or electronic device thermalmanagement applications as the technology is suitable for various otherapplications not related to thermal management of electronic devicessuch as but not limited to the application of a liquid to a surface ofan object. Therefore, the foregoing is considered as illustrative onlyof the principles of the invention. Further, since numerousmodifications and changes will readily occur to those skilled in theart, it is not desired to limit the invention to the exact constructionand operation shown and described, and accordingly, all suitablemodifications and equivalents may be resorted to, falling within thescope of the invention.

1. A dynamic spray cooling system for thermally managing a heatproducing device, comprising: a spray unit including an adjustableorifice, wherein said spray unit discharges a continuous coolant sprayhaving an adjustable spray characteristic; and a control unit incommunication with said spray unit, wherein said control unit transmitsa control signal to said spray unit for adjusting said adjustable spraycharacteristic of said continuous coolant spray; wherein said controlsignal is dependent upon a feedback data said control unit receives fromsaid spray unit; wherein said feedback data includes a measuredtemperature of a heat producing device being thermally managed.
 2. Thedynamic spray cooling thermal management system of claim 1, wherein saidspray characteristic includes a flow rate.
 3. The dynamic spray coolingthermal management system of claim 1, wherein said spray characteristicincludes a spray pattern.
 4. The dynamic spray cooling thermalmanagement system of claim 1, wherein said spray unit includes a swirlchamber and a swirl inlet.
 5. The dynamic spray cooling thermalmanagement system of claim 1, wherein said adjustable orifice iscomprised of a discharge orifice.
 6. The dynamic spray cooling thermalmanagement system of claim 1, wherein said adjustable orifice iscomprised of an inlet orifice fluidly connected to a swirl chamberwithin said spray unit.
 7. A dynamic spray cooling system for thermallymanaging a heat producing device, comprising: an atomizer including anadjustable orifice, wherein said atomizer discharges a continuouscoolant spray having an adjustable spray characteristic; and a controlunit in communication with said atomizer, wherein said control unittransmits a control signal to said atomizer for adjusting saidadjustable spray characteristic of said continuous coolant spray;wherein said control signal is dependent upon a feedback data saidcontrol unit receives from said atomizer; wherein said feedback dataincludes a measured temperature of a heat producing device beingthermally managed.
 8. The dynamic spray cooling thermal managementsystem of claim 7, wherein said spray characteristic includes a flowrate.
 9. The dynamic spray cooling thermal management system of claim 7,wherein said spray characteristic includes a spray pattern.
 10. Thedynamic spray cooling thermal management system of claim 7, wherein saidatomizer includes a swirl chamber and a swirl inlet.
 11. The dynamicspray cooling thermal management system of claim 7, wherein saidadjustable orifice is comprised of a discharge orifice.
 12. The dynamicspray cooling thermal management system of claim 7, wherein saidadjustable orifice is comprised of an inlet orifice fluidly connected toa swirl chamber within said atomizer.
 13. A dynamic spray cooling systemfor thermally managing a heat producing device, comprising: a heatproducing device; a spray unit, wherein said spray unit discharges acontinuous coolant spray having an adjustable spray characteristictoward said heat producing device to thermally manage said heatproducing device; and a control unit in communication with said sprayunit, wherein said control unit transmits a control signal to said sprayunit for adjusting said adjustable spray characteristic of saidcontinuous coolant spray.
 14. The dynamic spray cooling thermalmanagement system of claim 13, wherein said control signal is dependentupon a feedback data said control unit receives from said heat producingdevice.
 15. The dynamic spray cooling thermal management system of claim14, wherein said feedback data includes a measured temperature of saidheat producing device being thermally managed.
 16. The dynamic spraycooling thermal management system of claim 13, wherein said spraycharacteristic includes a flow rate.
 17. The dynamic spray coolingthermal management system of claim 13, wherein said spray characteristicincludes a spray pattern.
 18. The dynamic spray cooling thermalmanagement system of claim 13, wherein said spray unit includes a swirlchamber and a swirl inlet.